TY - CHAP A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk T1 - Remediation of cyanide-contaminated industrial sites through woody biomass production T2 - European Geosciences Union General Assembly 2017 Vienna, Austria, 23–28 April 2017 N2 - Due to the unfavourable chemical and physical soil quality parameters and the potential presence of contaminants, former industrial sites can hardly be utilized as arable land and can thus be classified as marginal areas. Still, as far as possible, they can effectively be used for the production of alternative energy, including the cultivation of fast growing trees. Apart from being a source of bioenergy, trees might facilitate the stabilization, remedation, contaminant extraction and degradation and, not on the last place, to enhance soil quality improvement on former industrial areas. This process is known as phytoremediation and has successfully been applied on industrial sites of various organic and inorganic contamination. The former manufactured gas plant site (� 2500 m2) “ehemalige Leuchtgasanstalt” Cottbus, contaminated, among others, with iron cyanides undergoes phytoremediation with simultaneous biomass production since 2011. The project “Biomass-Remediation” is fully financed by the German Railways JSC. A dense (23700 stems/ha), mixed cover of willow (Salix caprea), poplar (Populus maximowicii Henry x Populus trichocarpa Torr. et Gray (Hybrid 275)) and black locust (Robinia pseudoaccacia) trees has been planted on the site. Throughout the five years of remediation, a successful long-term stabilization of the site has been achieved as a result of the nearly outright established tree stock and the dense planting. Annual monitoring of the cyanide levels in the leaf tissue of the trees on the site and results from greenhouse experiments indicate the ability of all tree species to extract and transport the cyanide from the soil. Additonally, the greenhouse experiments suggest that the willows might be able, although not to a full extent, to detoxify the contaminant by splitting the CN moiety. The contaminated biomass material might easily be dealt with through regular harvests and subsequent incineration. Phytoremediation with simultaneous biomass production for bioenergy offers an environmenatlly-friendly and a cost-effective solution of the problem with contaminated former industrial areas in the context of marginal land use options. Y1 - 2017 UR - http://meetingorganizer.copernicus.org/EGU2017/EGU2017-6409.pdf N1 - EGU2017-6409 PB - European Geophysical Society CY - Katlenburg-Lindau ER - TY - CHAP A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk ED - Freese, Dirk ED - Pittruff, N. ED - Quinkenstein, Ansgar ED - Böhm, Christian T1 - Potential of selected agricultural crops to take up iron cyanides from contaminated soils T2 - Proceedings of the International Workshop on Agroforestry - Ecological Benefits of Agroforestry, 15-17 June 2011, Cottbus, Germany Y1 - 2011 UR - http://www-docs.tu-cottbus.de/multiland/public/FreeseEtAl2011_Proceedings_of_the_International_Workshop_on_Agroforestry.pdf SP - S. 26 ER - TY - GEN A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk T1 - Degradation of ferrocyanide by natural isolated bacteria T2 - International Journal of Phytoremediation N2 - This study aims at investigating the iron cyanide (CN) degradation potential of two natural bacterial isolates with the purpose of their application in iron CN phytoremediation. The strains were isolated from contaminated soil and incubated over 4 months with 50mg L⁻¹CN (as ferrocyanide) as the sole iron and nitrogen source. Unlike previous reports, the study provides control for bacterial growth, biotic and abiotic CN losses. Bacterial growth, CN, ammonium, and nitrate concentrations were monitored regularly. Both strains grew less rapid with iron CN compared with the positive control. However, the growth was diauxic. The CN concentration in the media decreased with 20% and 25% respectively, while that in the sterile controls remained stable. Ammonium was detected in the media of both strains implying that a fraction of the initially applied ferrocyanide has been converted. The nitrogen lost from the system evened out with that in the cells at the end of the experiments. These results showed that the investigated strains were undoubtedly able to grow on iron CN as an alternative nitrogen source, but contrary to some previous findings, the iron CN utilization is much slower and takes place only after complete exhaustion of the cellular nitrogen reserves. Y1 - 2019 U6 - https://doi.org/10.1080/15226514.2019.1633996 SN - 1549-7879 SN - 1522-6514 VL - 22 IS - 1 SP - 20 EP - 28 ER - TY - CHAP A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk ED - Böhm, Christian T1 - Phytoremediation und Biomasseerzeugung auf Industristandorten am Beispiel "ehemalige Leuchtgasanstalt" Cottbus T2 - Bäume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beiträgen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske) Y1 - 2017 UR - http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-41487 SN - 978-3-940471-27-7 SP - 196 EP - 201 PB - BTU CY - Cottbus ER - TY - GEN A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk ED - Orlovic, Sasa T1 - Degradation of ferrocyanide by natural isolated bacteria T2 - Book of Abstracts / The 15th International Phytotechnology Conference, 1-5 Octorber 2018, Novi Sad Y1 - 2018 SN - 978-86-912323-9-9 SP - 177 PB - University of Novi Sad CY - Novi Sad ER - TY - GEN A1 - Sut-Lohmann, Magdalena A1 - Fischer, Thomas A1 - Repmann, Frank A1 - Raab, Thomas A1 - Dimitrova, Tsvetelina T1 - Feasibility of field portable near infrared (NIR) spectroscopy to determine cyanide concentrations in soil T2 - Water, Air and Soil Pollution N2 - Vicinities of manufactured gas plants were often contaminated with solid iron–cyanide complexes as a result of the coal gasification process. During the remediation of affected soils, knowledge about contaminant concentrations is crucial, but laboratory methods are often expensive and time consuming. Rapid and non-destructive field methods for contaminant determination permit an analysis of large sample numbers and hence, facilitate identification of ‘hot spots’ of contamination. Diffuse near infrared reflectance spectroscopy has proven to be a reliable analytical tool in soil investigation. In order to determine the feasibility of a Polychromix Handheld Field Portable Near-Infrared Analyzer (FP NIR), various sample preparation methods were examined, including homogenizing, sieving, drying, and grinding. Partial least squares calibration models were developed to determine near infrared (NIR) spectral responses to the cyanide concentration in the soil samples. As a control, the contaminant concentration was determined using conventional flow injection analysis. The experiments revealed that portable near-infrared spectrometers could be a reliable device for detecting cyanide concentrations >2,400 mgkg−1 in the field and >1,750 mgkg−1 after sample preparation in the laboratory.We found that portable NIR spectrometry cannot replace traditional laboratory analyses due to high limits of detection, but that it could be used for identification of contamination ‘hot spots’. Y1 - 2012 U6 - https://doi.org/10.1007/s11270-012-1298-y SN - 1573-2932 VL - 223 IS - 8 SP - 5495 EP - 5504 ER - TY - GEN A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Raab, Thomas A1 - Freese, Dirk T1 - Uptake of ferrocyanide in willow and poplar trees in a long term greenhouse experiment T2 - Ecotoxicology N2 - Phytoremediation of sites contaminated with iron cyanides can be performed using poplar and willow trees. Poplar and willow trees were grown in potting substrate spiked with ferrocyanide concentrations of up to 2,000 mg kg-1 for 4 and 8 weeks respectively. Soil solution and leaf tissue of different age were sampled for total cyanide analysis every week. Chlorophyll content in the leaves was determined to quantify cyanide toxicity. Results showed that cyanide in the soil solution of spiked soils differed between treatments and on weekly basis and ranged from 0.5 to 1,200 mg l-1. The maximum cyanide content in willow and poplar leaves was 518 mg kg-1 fresh weight (FW) and 148 mg kg-1 FW respectively. Cyanide accumulated in the leaves increased linearly with increasing cyanide concentration in the soil solution. On the long term, significantly more cyanide was accumulated in old leaf tissue than in young tissue. Chlorophyll content in poplar decreased linearly with increasing cyanide in the soil solution and in leaf tissue, and over time. The inhibitory concentration (IC50) value for poplars after 4 weeks of exposure was 173 mg l-1 and for willow after 8 weeks of exposure—768 mg l-1. Results show that willows tolerate much more cyanide and over a longer period than poplars, making them very appropriate for remediating sites highly contaminated with iron cyanides. Y1 - 2015 U6 - https://doi.org/10.1007/s10646-014-1398-0 SN - 1573-3017 VL - 24 IS - 3 SP - 510 ER - TY - GEN A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk T1 - Detoxification of ferrocyanide in a soil-plant system T2 - Journal of Environmental Sciences N2 - The detoxification of iron cyanide in a soil–plant system was investigated to assess the total cyanide extracted fromcontaminated soil and allocated in the leaf tissue ofwillowtrees (Salix caprea). They were grown in soil containing up to 1000 mg/kg dry weight (dw) of cyanide (CN), added as 15N-labeled potassium ferrocyanide and prepared with a new method for synthesis of labeled iron cyanides. CN content and 15N enrichment were monitored weekly over the exposure in leaf tissue of different age. The 15N enrichment in the young and old leaf tissue reached up to 15.197‰and 9063‰, respectively; it increased significantly over the exposure and with increasing exposure concentrations (p < 0.05). Although the CN accumulation in the old leaf tissue was higher, compared to the young leaf tissue (p < 0.05), the 15N enrichment in the two tissue types did not differ statistically. This indicates a non-uniform CN accumulation but a uniform 15N allocation throughout the leaf mass. Significant differences were detected between the measured CN content and the C15N content, calculated fromthe 15N enrichment (p < 0.05), revealing a significant CN fraction within the leaf tissue, which could not be detected as ionic CN. The application of labeled iron CN clearly shows that CN is detoxified during uptake by the willows. However, these results do not exclude other detoxification pathways, not related to the trees. Still, they are strongly indicative of the central role the trees played in CN removal and detoxification under the experimental conditions. Y1 - 2019 U6 - https://doi.org/10.1016/j.jes.2018.06.005 SN - 1001-0742 VL - 77 SP - 54 EP - 64 ER - TY - GEN A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk T1 - Degradation of ferrocyanide by natural isolated bacteria T2 - International Journal of Phytoremediation N2 - This study aims at investigating the iron cyanide (CN) degradation potential of two natural bacterial isolates with the purpose of their application in iron CN phytoremediation. The strains were isolated from contaminated soil and incubated over 4 months with 50 mg L-1 CN (as ferrocyanide) as the sole iron and nitrogen source. Unlike previous reports, the study provides control for bacterial growth, biotic and abiotic CN losses. Bacterial growth, CN, ammonium, and nitrate concentrations were monitored regularly. Both strains grew less rapid with iron CN compared with the positive control. However, the growth was diauxic. The CN concentration in the media decreased with 20% and 25% respectively, while that in the sterile controls remained stable. Ammonium was detected in the media of both strains implying that a fraction of the initially applied ferrocyanide has been converted. The nitrogen lost from the system evened out with that in the cells at the end of the experiments. These results showed that the investigated strains were undoubtedly able to grow on iron CN as an alternative nitrogen source, but contrary to some previous findings, the iron CN utilization is much slower and takes place only after complete exhaustion of the cellular nitrogen reserves. KW - iron cyanide KW - detoxification KW - microorganisms Y1 - 2020 U6 - https://doi.org/doi:10.1080/15226514.2019.1633996 SN - 1522-6514 VL - Vol. 22 IS - 1 SP - 20 EP - 28 ER -